it seems that this file has disappeared since the 1.7 version (i.e. ten days ago!). However this version is not an official release, so we can't take that as granted. You should stick to the latest official release (http://svn.pointclouds.org/pcl/tags/pcl-1.6.0rc1/).
P.S. : of course you can also try to patch the code (by removing this include... and replacing it by another one if necessary?). Any feedback would be good then.
After searching a little bit in the PCL documentations i believe that the correct replacement for MovingLeastSquaresOMP is MovingLeastSquares but it seems i can`t make it work. It compiles all right but when i try to open a .pcd file the qcc seems unresponsive.